Comparison of Signal Generation Approaches for Component Testing at D-Band

This paper presents a comprehensive comparison of three distinct methodologies for generating wideband signals within the D -Band frequency range $(110 \mathrm{GHz}$ to 170 GHz). The first method employs a high-speed Arbitrary Waveform Generator (AWG) to directly generate the Intermediate Frequency (IF) vector modulated signal. The second approach involves generating the In-phase and Quadrature (IQ) signal at baseband and utilizing an IQ mixer for upconversion to the IF. The third method utilizes multiple high-resolution AWGs for IF signal generation and employs channel bonding to achieve the desired wide bandwidth. Subsequently, a D-Band upconverter is utilized to upconvert the IF signal to the target D-Band frequency. A comparative measurement is conducted by generating an 8 GHz bandwidth Orthogonal Frequency Division Multiplexing (OFDM) signal at 9.6 GHz, which is then upconverted to 158.4 GHz. Results demonstrate that the first, second and third approaches yield an Error Vector Magnitude of $\mathbf{1 . 5 \%}, \mathbf{0 . 8 \%}$, and $\mathbf{1 \%}$, respectively. Furthermore, component testing is conducted by generating a 2.6 GHz bandwidth OFDM signal at the same frequencies, and linearizing a D-Band amplifier with an 8 GHz linearization bandwidth. The first, second and third approaches achieved an Adjacent Channel Power Ratio of -45.8/-49.1 dBc, -60.9/-63.8 dBc and -58.4/-62.4 dBc, respectively.